Motor just went south

Took the pontoon in yesterday to have the carbs cleaned , and they called and it was 2 burnet pistons !
Been a good motor - 2000 Yamaha 50 - for 8 years , and have not had to do a thing to it. The bad part is that they said because of this time of the year they are looking at a 6 week turn a round. Oh well , I am putting it back in the slip , and will wait till the 1st of September to have it rebuilt. $2100.00 to boot. At least I have my Cajun bass boat as a stand by

The usual cause of burned pistons is a lean gas/air mixture. I'm betting that motor started exhibiting a lean sneeze a long time back and wasn't addresses at the time.

A too lean mixture probably means it wasn't getting sufficient oil thru the motor as well. Assuming it is a 2 stroke. Not enough oil can damage a lot of things. You will be lucky if it is only the rings/pistons.

Make sure they troubleshoot/isolate the cause of the burnt pistons.